Studies in vitro on amino acid incorporation into purified components of rat liver mitochondria.

نویسندگان

  • D S Beattie
  • G M Patton
  • R N Stuchell
چکیده

Several major protein components of the inner membrane were isolated from rat liver mitochondria after an incubation with (14C)leucine. No significant radioactivity was present in either the fraction containing the oligomycin-sensitive ATPase or that containing cytochromes b and cl. A variable amount of radioactive label was associated with a membranous preparation of cytochrome oxidase. After purification of this preparation to yield a highly purified and soluble cytochrome oxidase, however, a loss of radioactivity was observed. No counts were present in the two major bands observed after disc electrophoresis of the purified cytochrome oxidase. Three different methods were used to prepare a “structural” protein fraction which, in all three cases, appeared identical on polyacrylamide gel electrophoresis. The two structural protein fractions prepared with the use of dilute acid were not labeled, while the structural protein fraction prepared with bile salts and ammonium sulfate fractionation contained 40% of the total counts of the intact mitochondria. The radioactivity present in the latter structural protein fraction was not, however, present in any of the major bands visualized after disc electrophoresis but was retained with the small amount of material at the origin of the gel. It would thus appear that rat liver mitochondria in vitro do not incorporate amino acids into the major proteins of the structural protein fraction, cytochromes b and cl, cytochrome oxidase, or oligomycin-sensitive ATPase. Radioactive amino acids are incorporated in vitro into a heterogeneous insoluble membranous fraction which contains less than 10% of the total mitochondrial protein. The radioactivity in this fraction is associated to a significant degree only with the two slowest moving bands observed on disc electrophoresis plus the material retained at the origin of the gel. These results suggest that the proteins labeled by rat liver mitochondria in vitro are among the largest and least soluble of those in the mitochondrion.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Thyroxine stimulation of amino acid incorporation into protein. Localization of stimulated step.

Previous studies in this laboratory have demonstrated that the prior administration of L-thyroxine to animals in viva or its addition in vitro stimulates the rate of amino acid incorporation into microsomal protein in cell-free rat liver homogenates (3). Mitochondria and an oxidizable substrate were found to be essential requirements for the thyroxine effect in vitro; when these components of t...

متن کامل

Selective permeability of rat liver mitochondria to purified aspartate aminotransferases in vitro.

1. A method was devised to allow determination of intramitochondrial aspartate amino-transferase activity in suspensions of intact mitochondria. 2. Addition of purified rat liver mitochondrial aspartate aminotransferase to suspensions of rat liver mitochondria caused an apparent increase in the intramitochondrial enzyme activity. No increase was observed when the mitochondria were preincubated ...

متن کامل

Nucleic acids and protein synthesis in cancer cell mitochondria. II. Amino acid incorporation into proteins of rat liver and hepatoma cell mitochondria.

The energy source required for the amino acid incorporation into mitochondrial proteins has been investigated and comparative study has also been made on the rate of the amino acid incorporation in rat liver and rat hepatoma cell mitochondria. 1. The incorporation of amino acid into the protein in intact mitochondria of rat liver increased by about 40% on the addition of αketoglutarate and ADP,...

متن کامل

Thejournal of Biological Chemistry

Incorporation of plasma-bound iron into ferritin of liver and spleen of the rat is a dynamic process which accounts for 10% of the iron which normally leaves the plasma. It involves the reaction of adenosine triphosphate and ascorbic acid with iron bound to a &globulin of the plasma, transferrin, and leads to the transfer of this iron to ferritin. Evidence for this mechanism has been obtained f...

متن کامل

Amino acid incorporation by isolated rat liver mitochondria during liver regeneration.

Intact mitochondria, isolated from regenerating rat liver 2-3 days after partial hepatectomy, are 2.5-3 times more active in amino acid incorporation than mitochondria from control livers. Liver mitochondria from sham-operated animals showed normal amounts of incorporation. Sterile procedures insured low levels of bacterial contamination; cycloheximide was used to eliminate any contribution by ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Journal of biological chemistry

دوره 245 8  شماره 

صفحات  -

تاریخ انتشار 1970